We are not sure if the German communications regulator Bundesnetzagentur (BNetzA) will yield to Washington's warning as the country's federal cybersecurity agency has already rolled out the country's 5G security requirements, the requirements are quite strict, but not a complete and specific restrict on Huawei.
Perhaps anticipating China's complaint that the Trump administration is cracking down on Chinese electronics to drive them off the market and create business opportunities for American firms, Grenell advised the Germans to hire Ericsson Communications of Sweden, Nokia of Finland, or Samsung of South Korea to build its 5G network.
Germany's potential use of Huawei in its 5G rollout is a sticking point for the US.
Also on rt.com United States advises Italy to steer clear of China's new Silk Road... because it's a National Security issue? However, a CNBC report found that, under Chinese law, Huawei would be compelled by the Chinese government to assist with government surveillance if the government asks.
Germany, anxious to not get sucked into the maelstrom of an ongoing US-China spat over a multitude of issues including trade, has taken a cautious stance on the issue.
The Chinese telecoms behemoth has strenuously denied the espionage allegations.
Last week, Germany said it didn't want to ban Huawei from building its 5G network, noting that it'd tighten security around all vendors instead, Reuters reported.
The German Economy Ministry confirmed that the letter had been received.
While the U.S. embassy in Berlin would not confirm that a message was sent, the German Federal Economics Ministry did tell the Frankfurter Allgemeine Zeitung (FAZ - auf deutsch) that the letter had been received and would be "answered promptly".
Just last week, Huawei, which has vigorously denied the U.S.'s allegations, filed suit, challenging a us law that restricts federal agencies from using its gear.
Altmaier received the US letter on Friday - one day after he said Germany doesn't want to put an outright ban on Huawei. The company said it had a "solid track record in cybersecurity" and further accused the USA of breaking into its corporate systems, stealing information.